Research Interests
My research interests broadly encompass the molecular mechanisms underlying bacterial motility and pathogenesis, with a focus on the role that protein secretion plays in these processes.

Gliding Motility

For motility studies my lab uses the model organism Flavobacterium johnsoniae to study bacterial gliding motility, a process by which cells crawl over solid surfaces such as agar and glass. The exact mechanism underlying gliding motility remains unknown; however, genome analyses suggest this type of cell movement does not involve well-studied structures such as flagella or pili that drive other types of bacterial locomotion. Recent work has demonstrated that the cell surface components of the machinery are partially redundant, and loss of one component does not result in a complete loss of motility. As an example, one of the cell surface components required for spreading on agar surfaces is the large (670 kDa) adhesin protein SprB. Colonies of SprB-deficient mutants do not spread on agar surfaces, but individual cells do exhibit some motility when observed in wet mount. In addition, it appears that this adhesin is propelled along the cell surface, as latex spheres coated with anti-SprB antibody bind specifically to SprB on wild-type cells and are propelled rapidly around the cell. Current research on gliding motility is focused on:

In addition to motility, my lab is also interested in the mechanisms that bacterial pathogens use to cause disease. Work is currently focused on adapting the genetic techniques used for manipulating F. johnsoniae to the fish pathogens F. columnare and F. psychrophilum. Both of these organisms cause significant losses in the aquaculture industry each year, and development of new genetic techniques will allow us to knock-out target genes and evaluate their role in the disease process. Information gathered from these studies will provide a better understanding of the pathogenesis of these organisms and will help identify possible vaccine candidates. Current research on bacterial pathogenesis is focused on:

Developing an allelic exchange system in F. columnare and F. psychrophilum.